Effect of poultry waste feeding on intake, body weight and milk yield of Holstein cows.

Forty lactating Holstein cows were fed 0, 5.9, 11.7, or 17.4% processed poultry excreta in total mixed rations. The effect of treatment was evaluated on feed intake, BW, milk yield, and composition. Processes poultry excreta appeared to be well accepted by cows even when included in rations at 17.4% of total DM. Mean DM intake averaged 19.3, 19.7, 19.5, and 19.7 kg/d for cows fed 0, 5.9, 11.7, and 17.4% processed poultry excreta, respectively. Body weight change averaged 2.0, 1.7, -1.7, and 1.4 kg/wk from 90 to 180 d of lactation for cows fed from 0 to 17.4% processed poultry excreta, respectively. Fat-corrected milk (4%) yield was similar among treatment groups, averaging 24.2, 26.1, 24.6, and 25.1 kg/d for cows fed 0, 5.9, 11.7, and 17.4% processed poultry excreta. No differences were found for milk and fat yields of percentage fat among treatment means. No off flavors in milk could be attributed to processed poultry excreta added to feed. Processed poultry excreta fed up to 17.4% of total mixed rations supported both adequate feed intake and high milk yields of mid-lactation cows.

Effect of particle size of the calcium source on performance of broiler chicks fed diets with different calcium and phosphorus levels.

Broiler chicks were fed diets differing in calcium (Ca) level, source, and particle size. The basal diet fed in most experiments contained .62% total phosphorus and .49% Ca from sources other than the Ca sources being compared. Performance was not affected by Ca source in diets with .9% Ca. In diets with 1.5% Ca, gain and bone ash were significantly lower with a powdered, USP grade calcium carbonate than with limestone particles passing through a 1,000-mu screen and retained by a 417-mu screen. Crushing these particles to allow them to pass through a 74-mu screen caused them to behave like the powdered calcium carbonate. Particles of this limestone had to at least pass through a 147-mu screen to cause a greater reduction in gain; the finest particles tested (passed a 74-mu screen) reduced performance most. When graded levels of fine and medium particles were fed, the higher levels reduced gain, and less of the fine particles was required to produce a given reduction. In a high Ca-low P diet, fine particles of the Ca source were more deleterious than medium. Apparently, chicks can shunt excess Ca in the form of medium particles (150 to 1,000 mu) through the digestive system better than they can the more reactive, fine particles.

Comparison of DL-methionine and its sodium salt in water solution in broiler starter diets with two choline levels.

Graded levels of DL-methionine or a water solution of its sodium salt were added at equivalent levels to a broiler diet based on corn, soybean, and poultry by-product meals. Methionine addition to the basal diet produced only a small and statistically nonsignificant increase in gain. Gain/feed ratio was significantly increased by either methionine source; the two forms did not differ in value. Increasing the choline chloride added to the diet from 300 to 800 mg/kg did not improve performance nor reduce the value of the added methionine. The sulfur amino acid requirement of the broiler chicks was less than the .93% given by the National Research Council (1977).

Factors affecting efficacy of methionine hydroxy analogue for chicks fed amino acid diets.

Chicks were fed mixtures of methionine, cystine, and the calcium salt of the hydroxy analogue of methionine (MHA) in a diet based on a mixture of amino acids. Rate of gain with the basic amino acid diet containing a mixture of methionine and cystine was about 90% of the rate noted with a practical type diet. Efficacy of MHA depended on its level in the diet and on the levels of methionine and cystine fed with it. It was least effective when fed as the only sulfur amino acid or when fed with cystine. When fed with methionine it had intermediate value and was most efficacious when fed with a mixture of methionine and cystine. Essentially it was fully effective when it provided 25% of the sulfur amino acids with the remainder as equal parts of methionine and cystine. Replacing part of the cystine in a mixture of cystine and MHA with methionine resulted in a marked improvement in performance with L-methionine being slightly more effective than D-methionine.